With Sunday’s game at Providence Park tied, 1-1, the Dynamo were in position to advance when the second half began. They had to keep the Timbers from scoring again or score one more of their own.

Despite a defensive group that included only one regular starter, the Dynamo limited Portland to four on-target shots in large part because they limited their attack to the wide areas. The last thing the Dynamo wanted was Portland going straight up the gut.

They succeeded in that task, putting a cherry on top of the cake that has been their splendid defensive form over the last seven games.

“Credit to Houston,” Porter said. “Congratulations to them. I thought they defended exceptionally well tonight, especially their back four. (Adolfo) Machado and (Philippe) Senderos were men tonight.”